The invention relates to a high pressure valve having a valve cone guided by a valve spindle within a valve housing, which valve cone in its closed position engages an annular ridge of hard metal, in particular steel, consituting a valve seat.
Such valves make use of the plastic deformation to which the soft sealing surface is subjected when engaging the hard metal seat, to ensure a constant sealing effect of the valve over an extended period of time. Such a valve has been described, for instance, in German laid-open patent specification DE-A-1 190 756. In the known valves the valve cone is made of copper or of copper-plated or gold-plated steel, and is mounted on a conventional valve spindle, made, for instance, of steel. Such construction requires the separate manufacturing steps of assembly, and the plating of the valve cones, as the case may be.
Furthermore, steel spindles and valve cones made of steel have a high mass inertia which at periodic switching operations of the valve leads to a dynamic pressure loss in the range of about 4-5 bar. Finally, such cone/spindle structures are unsuited for actuation by an electromagnet as they are potentially subject to magnetization.